Automatic draft regulating device



Sept 1934. H. J. ROBERTS AUTOMATIC DRAFT REGULATING DEVICE Filed Jan. 26, 1935 2 Sheets-Sheet l l /az'i'y p I llomey H. J. ROBERTS 1,973,997

AUTOMATIC DRAFT lEGULATING DEVICE Sept. 18, 1934.

Filed Jan. 26, 1933 2 Sheets-Sheet 2 Patented Sept. 18, 1934 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to a novel device adapted to control or regulate the draft in a conduit of the type used in association with an air conditioning plant, such as for example a heating apparatus, ventilator, air cooler or the like.

Broadly stated, the inventive conception comprehends the provision of an appropriate valved duct or conduit arrangement wherein the intensity of both affluent and return or downdraft currents are automatically controlled to maintain a predetermined circulatory condition calculated to produce uniform combustion, a steady heat, to promote fuel economy and equivalent results depending on the character of apparatus in which the invention is embodied.

Stated more specifically the invention relates to an automatic valved vent susceptible of being built into the flue pipe or conduit, or applied thereto as an attachment, wherein said vent is particularly useful in maintaining a constant or uniform draft condition in the conduit irrespective of the external atmospheric or wind conditions.

In carrying the inventive conception into practice, I have evolved and produced a structure which is believed to be a mechanical achievement in this line of endeavor in that it is efiicient in performance, positive and dependable in action, simple and economical, and otherwise practicable in fulfilling the requirements of a device of this type.

The particular details selected and mechanically co-ordinated to accomplish the aforesaid results will become more readily apparent from the following description and drawings.

In the accompanying illustrative drawings wherein like numerals are employed to designate corresponding parts throughout the views:-

Figure l is a fragmentary perspective view ,40 showing a portion of a conduit or flue with the improved automatic valved vent device attached thereto.

Fig. 2 is a top plan view of the frame end of the device.

Fig. 3 is an end elevational view of Fig. 1 with the pipe removed.

Fig. 4 is a fragmentary sectional and elevational side View illustrating the relative positions of parts taken when the valve plate or damper swings inwardly under the action of suction.

Fig. 5 is a view similar to Fig. 4 showing the relative positions of parts when the plate swings outwardly under the action of pressure developed by excessive downdraft.

Fig. 6 is a detail view.

By way of introduction I would say that while the invention is adapted for use in connection with various types of air conditioning plants it is primarily adapted for use in conjunction with heating plants such as stoves, furnaces and equivalent structures. Hence for purpose of illustration the following description is directed more particularly to this specific use of the invention, it being understood that the alleged novelty is to be measured by the appended claims. Moreover, for sake of breadth of construction of the claims I will hereinafter use the expression conduit to represent a chimney, flue or equivalent duct or pipe.

Referring now to Fig. 1 of the drawings, it will be observed that the conduit or pipe is distinguished by the numeral '7, the left hand 8 thereof being adapted for attachment to the heating plant (not shown) and the right hand end 9 being adapted for connection with a chimney through which draft and particles of combustion pass in an obvious manner. The improved valved vent device is generally denoted by the numeral 10 and is adapted for connection with the conduit at a point intermediate the ends of the latter but preferably within the vicinity of the furnace, boiler or other source of heat.

The preferred embodiment of the device 10 comprises a relatively short laterally disposed branch pipe or thimble 11 whose inner end is connected as at 12 to an aperture formed in the pipe 7. This branch pipe may be of any appropriate proportions and cross section shape but is preferably as shown and provided at its outer end with a reinforcing and shaping rim 13. The valve plate or damper is distinguished by the numeral 14 and corresponds in shape to the frame and is supported in the frame. In fact, it is attached at its lower end rigidly to a horizontal oscillatory shaft 15 whose end portions are journalled for rotation in appropriate bearings. In the arrangement shown, the lower portions of the frame are simply formed with suitable holes 16 through which the ends of the shaft extend and have free movement and said end portions carry thrust washers 17 to afford freedom of movement of the valve plate.

The right hand end of the shaft is formed with 9, depending arm 18 carrying an adjustable counter-weight 19 held in place by a set screw 20. Thus the valve plate is normally maintained in a perpendicular or neutral position and its movement is counterbalanced through the agency or instrumentality of the weighted arm 18.

I next call attention to the numeral 21 which designates a pendulous one-way balancing and valve plate resisting device to effect the inward swinging movement of the valve plate as shown in Fig. 4. This device comprises a normally depending or perpendicular rod 22 having a hook 23 at its upper end suspended or hung over the adjacent projecting end portion of the shaft 15. A weight 24 is held in adjusted position through the medium of a set screw 25 and is carried by this rod. A special actuator or fixture is associated with the upper hooked end and this fixture comprises a block-like element 26 adjustably maintained in place on the extended end portion of the shaft 15 by way of the set screw 27. This actuator carries a grooved flange or abutment 28 which is movable in a path to engage the hooked end portion of the rod 22 when the shaft 15 is oscillated in a direction to swing the valve plate 14 inwardly. Manifestly, however, this lug or flange 28 has no effect whatsoever on the position of the rod 22 when the valve plate swings outwardly under the action of exhausting downdraft pressure. In other words as shown in Fig. 5 when the plate swings outwardly the rod 22 simply hangs down in a perpendicular position so that it is non-resistant to the outward swinging motion of the valve plate.

The gist of the invention is found in the provision of a suitably constructed branch pipe, nipple, thimble or equivalent enclosure which is attached to the apertured portion of the main conduit or pipe '7 to project laterally therefrom as shown in Fig. 1, wherein said branch pipe is provided at its outer end portion with a draft actuated valve plate swingable through a limited arc to diversified positions according to the draft conditions existing in the conduit. Under external high wind or reverse atmospheric conditions where the intensity of the draft develops an unusually strong circulation, the affluent current reacts on the valve plate 14 by suction to swing it inwardly to the approximate position illustrated in Fig. 4 to open the vent and to relieve such undesirable intensified drafting condition. In the other extreme position illustrated in Fig. 5, the valve plate has been swung outwardly beyond the branch pipe 11 so as to permit dangerous back or downdraft currents to exhaust and to relieve abnormal pressure conditions in the chimney or flue whereby to relieve the source of heat of the undesirable effect of such abnormal return draft results.

While the preferred embodiment of the invention has been shown and described, it is to be understood that minor. changes may be made within the field of invention claimed without departing from the spirit of the invention.

Having thus described my invention, what I claim as new is:

1 A draft regulating device of the class described comprising a casing-like branch pipe for attachment to a draft circulating conduit, a horizontal shaft mounted for oscillation at the outer end portion of said pipe, said shaft being provided at one end with a depending arm, a counter-balancing weight adjustably mounted on said arm, a valve plate rigidly connected to the shaft and constructed to substantially close the adjacent end portion of the pipe, .the opposite end of said shaft projecting beyond the pipe, a rod having a hook formed at its upper end engaged over said projecting end, an adjustable weight carried by said rod, an adjustable collar on the extending end of the shaft, and a projection on the collarhaving a part extending about the hook on one side thereof, whereby the shaft will rotate the rod only when the shaft is rotated in one direction from its normal position.

2. The combination of a pipe having an opening therein, damper means hingedly supported at one end for swinging movement into and out of the opening, gravitational weight means connected with the damper means and arranged to yieldingly maintain the damper means under normal conditions in position closing the opening, and other gravitational weight means connected with the damper means and arranged to yieldingly maintain the damper means against inward movement from its normally closedposition.

HARRY J. ROBERTS. 

